1. Field of the Art
The present exemplary embodiments relate to a system and method for powering gas-filled lamps using radio and/or microwave frequencies.
2. Description of the Related Art
Compact fluorescent lamps are a special type of fluorescent lamp designed for a condensed space. Compact fluorescent lamps are designed with dimensions and specifications which allow them to fit into existing light fixtures that are typically designed for traditional incandescent light lamps. Compact fluorescent lamps typically comprise: a gas-filled spiral tubular glass lamp, a ballast, and filaments. The gas-filled spiral tubular glass lamp typically contains a small amount of mercury, an inert gas such as argon, a phosphor coating, and other materials and gases. All of these substances are contained within the spiral tubular glass lamp under low pressure conditions compared to that of atmospheric pressure. Filaments coated with an oxide compound extend into the gas-filled spiral shaped glass lamp at each end. Each filament is also typically connected to an electronic ballast, which is coupled to the gas-filled spiral tubular glass lamp and forms the base of the compact fluorescent lamp. Often, electronic ballasts contain a small circuit board with electronic components for providing power to the lamp.
Typically, the electronic ballast connects to an alternating current (“AC”) power source operating at a nominal voltage of 120 volts and a frequency of about 50-60 Hz, which powers the compact fluorescent lamp. Each filament receives current, through the ballast, thereby heating the filaments thus providing electrons to the gas filled spiral tubular glass lamp. Another voltage is applied to the filaments that drives electrons into the gas-filled spiral tubular glass lamp. The result of these voltage driven filament supplied electrons is that the originally neutral gas atoms and/or molecules undergo excitation and ionization within the gas. Due to the composition of the gases and substances within the spiral tubular glass lamp, this process results in the emission of light from the gas-filled spiral tubular glass lamp when the compact fluorescent lamp is provided power from a power source.
The filaments located within the compact fluorescent lamp operate by receiving electric current from the ballasted power supply. The electric current passes through the filament, creating heat and providing electrons. Voltage applied to the filaments forces electrons into the gas-filled region within the spiral tubular glass lamp, eventually resulting in light emission from the compact fluorescent lamp.
Compact fluorescent lamps provide advantages over traditional incandescent lamps. One advantage is that compact fluorescent lamps are capable of emitting the same amount of light as an incandescent lamp, while using much less power. Because they consume less power, under certain conditions, compact fluorescent lamps can give substantial energy cost savings when compared with standard incandescent light lamps. Furthermore, many compact fluorescent lamps comprise an Edison screw or a bayonet fitting, thereby making the compact fluorescent lamps compatible with many standard incandescent light fixtures.
While compact fluorescent lamps provide substantial energy efficiency benefits when compared with incandescent lamps, they are also more expensive to manufacture and purchase than incandescent lamps. Furthermore, compact fluorescent lamps have a limited switching life span compared to incandescent lamps. The switching life span (SLS) refers to the number of switch ON and switch OFF cycles. SLS is generally not quoted by the manufacturer, but instead the manufacturer quotes the constant ON time in hours. On average, compact fluorescent lamps have a limit of approximately 9,500 switching cycles before experiencing filament failure or burnout. Generally, filament failure or burnout occurs for one of two fundamental mechanisms: 1) sputtering erosion of the low work function oxide coating; or 2) breakage of the filament. Also, both mechanisms may occur in a single filament. Additionally, the ballast may fail but this occurs much less frequently than filament failure. Once filament failure or burnout occurs, the compact fluorescent lamp is inoperable or “dead” under standard AC operating power conditions. Accordingly, consumers are forced to purchase and replace the expensive compact fluorescent lamp.
Therefore, there is a need for an alternative system and method to operate standard compact fluorescent lamps after filament failure or burnout that is cost-effective, environmentally friendly, and energy efficient. The foregoing embodiments describe a method and system for powering and/or restoring compact fluorescent lamps using radio frequency (RF) power. The method and system described herein successfully restores compact fluorescent lamps that are inoperable or “dead” under standard AC operating conditions, which reduces landfill impact and the environmental impact of toxic mercury due to discarded lamps, in addition to maintaining energy efficiency.
The description herein of certain advantages and disadvantages of known methods and devices is not intended to limit the scope of the present invention. Indeed, the exemplary embodiments may include some or all of the features described above without suffering from the same disadvantages.